TWI662099B - Adhesive composition for polarizer and adhesive sheet for polarizer - Google Patents

Abstract

The object of the present invention is to provide an adhesive composition and an adhesive sheet for polarizers, which are anti-static performance adhesive compositions for polarizers, and even if the polarizers are directly adhered to the polarizers, the discoloration of the polarizers does not occur. Or deterioration. The present invention relates to an adhesive composition for a polarizer, which is characterized by containing an antistatic composition; the above-mentioned antistatic composition is a plasticizer containing a polyether group in the main chain, and is dissolved with fluorine. And an anionic salt of a sulfonyl group.

Description

Adhesive composition for polarizer and adhesive sheet for polarizer

The present invention relates to an adhesive composition for a polarizer and an adhesive sheet for a polarizer. Specifically, it relates to the adhesive composition for polarizers and the adhesive sheet for polarizers which are directly attached to a polarizer, and which are bonded to an optical member.

In the liquid crystal cell of a liquid crystal display device (LCD), depending on the image forming method, it is sometimes necessary to arrange polarizing plates on both sides of the display substrate. On one side of the polarizing plate, an adhesive layer for attaching to other optical parts such as the liquid crystal cell is formed. .

Generally, a polarizing plate is a transparent protective film provided on both surfaces of a polarizer made of a polyvinyl alcohol-based film and a dichroic pigment such as iodine. The polarizer is weak in physical strength and is prone to breakage in the processing direction. Therefore, the transparent protective film is bonded to at least one side, usually two sides, through an adhesive layer. The polarizing plate used in the conventional liquid crystal cell is a three-layer structure in which polarizers are held between two triacetyl cellulose (TAC) protective films, or a TAC protective film and a cycloolefin polymer. (COP) is a three-layer structure with polarizers held between protective films.

When a polarizing plate is stuck to a liquid crystal cell or the like, an adhesive is usually used. Since the polarizing plate can be instantly fixed, and a drying step is not required when the polarizing plate is fixed, the adhesive is arranged on one side of the polarizing plate as an adhesive layer in advance.

When a polarizing plate is bonded to a liquid crystal cell, static electricity may occur. This kind of static electricity is caused by the failure of the liquid crystal cell or the adsorption of foreign matter due to the charge. Due to the foreign matter jamming, the adhesive layer must have antistatic properties. For example, Patent Documents 1 to 3 generally contain an ionic compound in order to provide an antistatic property to the adhesive layer.

In addition, in recent years, due to the thinning of touch panels such as smart phones, the optical components of liquid crystal cells have also become thinner. A polarizing plate is no exception, and a polarizing plate having a protective film formed on at least one side of a polarizer instead of a transparent protective film has been proposed (Patent Document 4). In addition, a polarizing plate having a protective film for improving durability under severe environments has been proposed (Patent Document 5). Furthermore, in order to reduce the thickness of the polarizing plate, a polarizing plate having a transparent protective film on the side where the adhesive layer of the polarizing plate is disposed, and an adhesive layer directly provided on the polarizer is reviewed.

[Prior technical literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2013-100386

[Patent Document 2] Japanese Patent Laid-Open No. 2013-108031

[Patent Document 3] Japanese Patent Laid-Open No. 2014-62264

[Patent Document 4] Japanese Patent Laid-Open No. 2003-185842

[Patent Document 5] Japanese Patent Laid-Open No. 2010-9027

However, according to the review by the inventors, it is known that when the transparent protective film of the polarizer is canceled and an adhesive layer is directly provided on the polarizer, if a conventional adhesive layer having antistatic properties is used, it may be polarized. Discoloration (deterioration of polarizer) of dichroic pigments, such as iodine, which are adsorbed and aligned by polyvinyl alcohol (PVA) situation.

Therefore, the present inventors and others continue to study, and the purpose is to provide an adhesive composition and an adhesive sheet for polarizers, which are adhesive compositions with antistatic properties, and do not occur even when directly attached to the polarizer. Discoloration or deterioration of polarizers.

The present inventors investigated the cause in order to solve the above problems, and found that the cause of the discoloration of the polarizer is the antistatic agent contained in the adhesive layer for imparting antistatic properties. Therefore, the inventors of the present inventors made further intensive studies, and found that by using an antistatic agent having a specific composition as the adhesive composition, the antistatic performance can be prevented and the discoloration of the polarizer can be suppressed. Specifically, the present inventors have found that a plasticizer containing a polyether group in the main chain is stabilized by dissolving an antistatic composition having a salt having an anion having a fluorine group and a sulfofluorenyl group. And it is evenly dispersed in an acrylic adhesive, and when this is used for bonding a polarizer and an optical member, the antistatic performance can be prevented and the discoloration of the polarizer can be suppressed. Furthermore, the present inventors have found that the use of such an adhesive composition for polarizers can reduce the thickness of a polarizing plate, and completed the present invention.

Specifically, the present invention has the following configuration.

[1] An adhesive composition for polarizers, characterized in that it contains an antistatic composition; the antistatic composition is a plasticizer containing a polyether group in the main chain, and has a fluorine group and Composition of an anionic salt of a sulfonyl group.

[2] The adhesive composition for polarizers according to [1], wherein the antistatic composition is a polyether ester-based plasticizer containing a polyether group in a main chain, and has a fluorine group and a sulfone Composition of an anion salt of a fluorenyl group.

[3] The adhesive composition for polarizers according to [2], wherein the polyether ester plasticizer contains at least one polyether ester plasticizer represented by the following formula (1) or (2);

In formula (1) and formula (2), m and n are each an integer, and R represents an alkyl group.

[4] The adhesive composition for polarizers according to [1], wherein the antistatic composition is a polyether plasticizer containing a polyether group in the main chain, and has a fluorine group and a sulfonium An anionic salt composition.

[5] The adhesive composition for polarizers according to [4], wherein the polyether plasticizer contains a polyether plasticizer having the following formula (11); R ¹ (OCH ₂ CH ₂ ) _n OR ² ( 11)

In the formula, R ¹ represents an alkyl group having 1 to 12 carbon atoms, R ² represents a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, and n represents an integer of 3 to 6.

[6] The adhesive composition for polarizers according to [1], wherein the antistatic composition contains a polyether ester-based plasticizer containing a polyether group in a main chain, and is dissolved with a fluorine group. A composition containing a salt of an anion having a sulfofluorenyl group and a polyether plasticizer containing a polyether group in the main chain, a composition having a salt having an anion having a fluoro group and a sulfonyl group dissolved therein.

[7] The adhesive composition for polarizers according to any one of [1] to [6], wherein the adhesive composition for polarizers is an adhesive composition whose main component does not substantially contain a carboxyl group.

[8] The adhesive composition for a polarizer according to any one of [1] to [7], wherein the main component of the adhesive composition for a polarizer is an acrylic adhesive composition.

[9] The adhesive composition for a polarizer according to [8], wherein the acrylic adhesive composition contains a (meth) acrylic copolymer (A) and a crosslinking agent (B); (meth) acrylic acid The copolymer (A) is a (meth) acrylic acid ester monomer having at least (i) an alkyl group having 1 to 18 carbon atoms and having a radical polymerizable unsaturated group of 60 to 99.99% by mass, and (ii) A monomer having at least one reactive functional group is obtained by polymerizing 0.01 to 20% by mass.

[10] The adhesive composition for polarizers according to [9], wherein the reactive functional group is selected from at least one of a hydroxyl group and an amine group, and the monofunctional system having a reactive functional group does not substantially contain a carboxyl group-containing monomer. body.

[11] The adhesive composition for polarizers according to [9] or [10], wherein the cross-linking agent (B) is selected from the group consisting of isocyanate-based cross-linking agents, epoxy-based cross-linking agents, and metal clamp-based cross-linking agents. At least one combination.

[12] The adhesive composition for a polarizer according to any one of [9] to [11], wherein the content of the antistatic composition is based on 100 parts by weight of the (meth) acrylic copolymer (A). It is 0.01 to 30 parts by mass.

[13] The adhesive composition for a polarizer according to any one of [1] to [12], wherein the anion system having a fluoro group and a sulfofluorenyl group is selected from the group consisting of bis (fluoroalkylsulfonyl) fluorenimide Anions consisting of ions, gins (fluoroalkylsulfonyl) methyl metal compound ions and fluoroalkylsulfonic acid ions.

[14] The adhesive composition for a polarizer according to any one of [1] to [13], wherein the salt system including an anion having a fluorine group and a sulfonyl group includes a salt selected from the group consisting of alkali metals ,2 At least one cation of a group element, a transition metal, and an amphoteric metal; and an anion having a fluorine group and a sulfonyl group.

[15] The adhesive composition for a polarizer according to any one of [1] to [14], wherein the salt system having an anion having a fluoro group and a sulfofluorenyl group is selected from the group consisting of bis (fluoroalkylsulfonyl) A salt composed of an alkali metal salt of fluorenimine, an alkali metal salt of a gins (fluoroalkylsulfonyl) methyl metal compound, and an alkali metal salt of trifluoroalkylsulfonic acid.

[16] The adhesive composition for a polarizer according to any one of [1] to [15], wherein the adhesive composition for a polarizer is used for bonding a polarizer to an optical member.

[17] The adhesive composition for a polarizer according to [16], wherein the optical member is a liquid crystal cell or a touch panel.

[18] An adhesive sheet for a polarizer, comprising the adhesive composition for a polarizer according to any one of [1] to [17].

[19] An image display device, comprising at least one adhesive sheet of [18].

According to the present invention, even if the adhesive composition is directly adhered or laminated on at least one side of the polarizer, the adhesive composition for polarizers that does not impair the antistatic performance and does not cause discoloration or deterioration of the polarizer and Adhesive sheet for polarizers. These polarizers are directly attached to the polarizer with an adhesive composition or an adhesive sheet, and the polarizer and the optical member are attached via the polarizer adhesive composition or the polarizer adhesive sheet. Therefore, the thickness of the polarizing plate can be reduced.

1‧‧‧ polarizing plate

10‧‧‧Polarizer

12‧‧‧ protective film

20‧‧‧Adhesive sheet (adhesive composition layer for polarizers)

FIG. 1 is a diagram illustrating the effect of the antistatic composition used in the present invention.

Figures 2 (a) and (b) are illustrations showing the polarization of the adhesive composition containing the polarizer of the present invention; The structure of a light plate and the structure of a conventional polarizer.

FIG. 3 is a HPLC (high-speed liquid chromatography) layer of the antistatic composition, the extract of the adhesive sheet containing the antistatic composition, and the extract of the adhesive sheet without the antistatic composition used in the examples. Analysis of pictures.

The present invention is explained in detail below. The description of the constituent elements described below is based on typical embodiments or specific examples, but the invention is not limited to such embodiments. In addition, in this specification, the numerical range represented by "~" means the range including the numerical value described before and after that as a lower limit value and an upper limit value.

(Adhesive composition for polarizers)

The adhesive composition for a polarizer of the present invention is an adhesive composition that is directly attached to at least one side of the polarizer and is used to adhere the polarizer and the optical member. The adhesive composition for polarizers of this invention contains an antistatic composition. Here, the antistatic composition is a composition in which a salt having an anion having a fluorine group and a sulfonyl group is dissolved in a plasticizer containing a polyether group in a main chain. Since the adhesive composition for polarizers of the present invention has the above-mentioned structure, the polarizer and the adhesive layer are softly and tightly adhered. In addition, since the adhesive composition for a polarizer of the present invention can be directly attached or laminated to a polarizer, a thin polarizing plate without a transparent protective film or a protective layer can be manufactured. In this way, even if a polarizing plate such as a protective film is eliminated, the heat resistance is excellent in a high temperature or high temperature and high humidity environment or an environment where repeated heating and cooling are performed, and it is possible to suppress a more intense temperature history or an adhesive component (mainly antistatic). Discoloration (deterioration) of the polarizer caused by the movement of the components).

(Antistatic composition)

The antistatic composition used in the adhesive composition for polarizers of the present invention is a composition in which a salt having an anion having a fluorine group and a sulfonyl group is dissolved in a plasticizer containing a polyether group in a main chain. Thing. That is, in the antistatic composition, a salt having an anion having a fluorine group and a sulfonyl group is dispersed in a dissolved state in a plasticizer containing a polyether group in the main chain.

In addition, the antistatic composition used in the adhesive composition for polarizers of the present invention is also dissolved in a plasticizer containing a polyether group in the main chain, and has an element selected from the group consisting of alkali metals, group 2 elements, and transitions. Composition of cation salt of at least one of metal and amphoteric metal. The cation is preferably a cation selected from any one of an alkali metal and a Group 2 element, and more preferably a cation of an alkali metal. Among these, the cation is preferably a lithium ion.

Here, in the adhesive composition for a polarizer of the present invention, a cation belonging to a counter ion of an anion is coordinated with an oxygen atom of an ether in a plasticizer to form a complex. That is, a cation that belongs to the opposite ion of an anion having a fluorine group and a sulfonyl group is a Lewis acid-base type ion formed with a plasticizer containing a polyether group in the main chain. The antistatic composition used in the present invention is characterized in that an oxygen atom of an ether contained in a plasticizer containing a polyether group in a main chain is coordinated with a counter ion belonging to an anion having a fluorine group and a sulfonyl group. Cation complex.

The cation that forms the wrong ion with the plasticizer is preferably a cation selected from at least one of an alkali metal, a Group 2 element, a transition metal, and an amphoteric metal, and more preferably a lithium ion. That is, the complex formed is preferably a lithium polyether complex.

The antistatic composition used in the adhesive composition for a polarizer of the present invention detects a peak derived from a complex when it is analyzed by HPLC (high-speed liquid chromatography). This peak is a peak derived from a complex, which is not detected when the salt has an antistatic composition or only a plasticizer containing a polyether group in the main chain.

The HPLC conditions are as follows.

Column: XBridge C18, diameter 4.6 × 250mm (made by WATERS)

Column temperature: 30 ℃

Mobile phase: acetonitrile / water

Flow rate: 0.8mL / min

Detection: 225nm

In the present invention, by using such an antistatic composition, the polarizer can be prevented from discoloring even when the adhesive composition is directly attached to the polarizer. In the present specification, the term "dispersed" refers to a state in which a salt having an anion having a fluorine group and a sulfonyl group is dispersed or dissolved in a plasticizer. Examples of such an antistatic composition include Sankonol AD2326 (manufactured by Sanko Chemical Industry Co., Ltd.), Sankonol AD2600 (manufactured by Sanko Chemical Industry Co., Ltd.), Sankonol TGR (manufactured by Sankom Chemical Industry Co., Ltd.), and the like.

If a conventional adhesive composition for polarizers containing an ionic compound is directly attached to the polarizer, the ionic compound has poor fluidity or poor compatibility with the acrylic adhesive composition, so cations exudate or glow. Blooming, forming a pseudo-bond with the iodine ions (I ^3- , I ^5- ) of the polarized photon, causing discoloration of the polarizer. On the other hand, since the antistatic composition used in the present invention is dispersed in a plasticizer having a high affinity with the acrylic adhesive composition, it does not cause bleeding or dispersal. Furthermore, the cations of the antistatic composition do not form chemical bonds with the iodine ions of the polarizer because they form Lewis acid and base type ions with the plasticizer.

The content of the antistatic composition is preferably 0.01 to 30 parts by mass based on 100 parts by mass of the (meth) acrylic copolymer in the adhesive composition for polarizers. Mass parts, more preferably 0.1 to 10 mass parts. When the content of the antistatic composition is within the above range, sufficient antistatic performance can be exhibited, and adverse conditions such as precipitation of the antistatic composition can be suppressed in a low temperature environment.

(Polyether ester plasticizer)

The antistatic composition is preferably a composition in which a salt having an anion having a fluorine group and a sulfonyl group is dissolved in a polyether ester plasticizer containing a polyether group in the main chain. Polyether ester plasticizers contain a polyether group and an ester bond, and enter the resin gap to prevent regular alignment of the resin. The polyether ester-based plasticizer is one that maintains an amorphous state even below the glass transition point. Among these, the polyetherester-based plasticizer is preferably a polyetherester-based compound represented by the following formula (1) or (2).

In formulae (1) and (2), m and n are integers, and R represents an alkyl group.

Polyether ester plasticizers have low viscosity and good workability. They have low temperature flexibility, balance between heat aging resistance, softness and durability, non-volatile, non-migration, oil resistance and safety (suitable for PL) .

R is preferably an alkyl group having 1 to 14 carbon atoms. For example, methyl, ethyl, N-propyl, isopropyl, n-butyl, isobutyl, n-pentyl, n-nonyl, isononyl, n-decyl, n-lauryl and the like.

In the formulae (1) and (2), m is preferably an integer of 1 to 40, and n is preferably an integer of 1 to 20. m and n are more preferably an integer of 2 or more. m is particularly preferably an integer of 2 or more.

The polyether ester-based plasticizer containing a polyether group in the main chain preferably has a molecular weight of 250 to 2,000, more preferably 500 to 1500. The viscosity (25 ° C) of the polyether ester plasticizer is preferably 30 to 600 mPa‧s.

(Polyether plasticizer)

The antistatic composition may be a composition in which a salt having an anion having a fluorine group and a sulfonyl group is dissolved in a polyether plasticizer containing a polyether group in the main chain. The antistatic composition may be a composition containing a polyether ester-based plasticizer containing a polyether group in a main chain in which a salt having an anion having a fluorine group and a sulfonyl group is dissolved; and a main chain A composition containing a salt having an anion having a fluorine group and a sulfonyl group is dissolved in a polyether plasticizer containing a polyether group. Here, the so-called polyether plasticizer is preferably a polyalkylene glycol (di or mono) alkyl ether compound represented by the following general formula (11).

R ¹ (OCH ₂ CH ₂ ) _n OR ² (11)

In the formula (11), R ¹ represents an alkyl group having 1 to 12 carbon atoms, R ² represents a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, and n represents an integer of 3 to 6.

The polyether plasticizer is particularly preferably a polyalkylene glycol alkyl ether compound.

(Other plasticizers)

Furthermore, the antistatic composition is in addition to the above-mentioned polyether ester-based or polyether-based plasticizers. In addition, it may contain other plasticizers. As such a plasticizer, for example, an ester formed from a mono or dicarboxylic acid having a saturated or unsaturated acyclic hydrocarbon group and an alcohol having an acyclic hydrocarbon group having 1 to 20 carbon atoms, or an unsaturated one Plasticizers in which unsaturated groups in acyclic hydrocarbon groups are epoxidized esters. By using this kind of ester, the wettability of the adhesive layer to the adherend can be improved, it is not easy for the bubble to be involved during the attachment, and it is not easy for the plasticizer to leak out from the adhesive layer, which can be suitable to reduce the contamination by the adhesive.

As the saturated or unsaturated acyclic hydrocarbon group in the mono- or dicarboxylic acid component constituting the ester, for example, an alkyl group or an alkylene group may be mentioned. Among them, an alkyl group or an alkylene group having 1 to 20 carbon atoms is preferred, and more An alkyl group having 4 to 18 carbon atoms is preferred, and an alkyl group having 4 to 14 carbon atoms is particularly preferred. Such a mono- or dicarboxylic acid having a saturated or unsaturated acyclic hydrocarbon group has a carbon number close to that of an acrylic monomer having an acrylic adhesive composition used to constitute the adhesive composition for a polarizer. Carbon number, and compatibility with the adhesive composition for polarizers is good, and it is suitable to be held in the adhesive composition for polarizers, so that the bleedout is suppressed.

Examples of the monocarboxylic acid and dicarboxylic acid having a saturated or unsaturated acyclic hydrocarbon group include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, and azelaic acid. Mono- or polyesters of linear aliphatic dicarboxylic acids such as acids, sebacic acid, dodecanedioic acid, etc., acetic acid, propionic acid, butyric acid, valeric acid, hexanoic acid, heptanoic acid, caprylic acid, nonanoic acid, capric acid Saturated fatty acids such as, undecanoic acid, lauric acid, tridecanoic acid, myristic acid, pentadecanoic acid, palmitic acid, heptadecanoic acid, stearic acid, undecanoic acid, and osmic acid, crotonic acid, behenic acid, twelve Enoic acid, myristate oleic acid, palmitic oleic acid, oleic acid, isoleic acid, cocoic acid, pinenoic acid, erucic acid, panearic acid, linoleic acid, carbodienoic acid, cydiadicarbonate Enoic acid, octadecadienoic acid, pine oleic acid, tungstic acid, succinic trienoic acid, octacosatetraenoic acid, arachidonic acid, cincosatetraenoic acid, succinic acid Unsaturated fatty acids such as arsenoic acid.

As the acyclic hydrocarbon group having 1 to 20 carbon atoms in the alcohol constituting the ester, an alkyl group having 1 to 20 carbon atoms or an alkylene group, especially an alkyl group can be suitably used. Among them, an alkyl group having 4 to 18 carbon atoms is preferred. Radicals, particularly preferred alkyl radicals having 4 to 14 carbon atoms. Such an alcohol having a saturated or unsaturated acyclic hydrocarbon group has a carbon number close to the carbon number of an acrylic monomer having an acrylic adhesive composition constituting the adhesive composition for a polarizer. On the other hand, it has good compatibility with the adhesive composition for polarizers, and is suitable for being held in the adhesive composition for polarizers, so that it can suppress bleeding. Compared with the carboxylic acid component constituting the ester, the carbon number of the hydrocarbon group having the alcohol component is set closer to the carbon number of the acrylic monomer constituting the acrylic adhesive composition of the acrylic adhesive composition for the polarizer. Carbon number, it is particularly easy to suppress contamination by slime.

Examples of such an alcohol having an acyclic hydrocarbon group include methanol, ethanol, propanol, butanol, pentanol, hexanol, heptanol, octanol, nonanol, decanol, undecanol, dodecanol, Tridecyl alcohol, myristyl alcohol, pentadecyl alcohol, cetyl alcohol, heptadecyl alcohol, stearyl alcohol, nonyl alcohol, arachidyl alcohol, branched alcohol. Among them, particularly preferred are butanol, pentanol, hexanol, heptanol, octanol, nonanol, and decanol.

In the present invention, in addition to the above-mentioned polyether ester-based plasticizer and / or polyether-based plasticizer, an ester formed from the above-mentioned mono- or dicarboxylic acid and an alcohol may be used as the plasticizer. The ester may be one having a skeleton composed of a saturated or unsaturated hydrocarbon group, and is preferably an ester having no skeleton composed of an unsaturated hydrocarbon group. In addition, an epoxidized ester in which an unsaturated bond of an ester having a skeleton composed of the unsaturated hydrocarbon group is epoxidized is preferably used. Among the esters, adipic acid monoester, sebacic acid monoester, and epoxidized fatty acid monoester are particularly preferred.

The ester used as a plasticizer may be either a monoester or a polyester. The solubility parameter (SP value) can be easily controlled to an appropriate range, and the adhesive group for polarizers can be used. For the compatibility of the product to be easily improved, it is preferably an ester having a weight average molecular weight of 1,000 or less in terms of PS conversion, and particularly preferably an ester of 300 to 800.

As the plasticizer, a plasticizer having a solubility parameter (SP value) of 8.5 or less is preferably used. Among them, it is preferably 7.0 to 8.4. If the SP value of the plasticizer is 8.5 or less, the compatibility with the acrylic adhesive composition is excellent. Therefore, even in a state where the adhesive composition for a polarizer is attached depending on the polarizer, it has a long life in a high temperature and high humidity environment. In the case of standing for a long time, when the surface of the polarizer is peeled off, fogging is still not easy to occur on the surface of the polarizer. As the SP value of the plasticizer, a plasticizer larger than 7.0 is commonly used. The SP value is a calculated value based on the Small's formula [P.A.J.Small: J.Appl.Chem., 3,71 (1953)] advocated by J.Small.

The plasticizer is preferably added to 0.5 to 30 parts by mass, more preferably 1 to 20 parts by mass, and particularly preferably 1 to 10 parts by mass with respect to the (meth) acrylic copolymer which constitutes the acrylic adhesive composition. If the added amount of the plasticizer is more than 0.5 parts by mass, bubbles will be easily detached during bonding. In addition, if it is less than 30 parts by mass, fogging is unlikely to occur on the display surface even in a high temperature and high humidity environment.

(A salt having an anion having a fluoro group and a sulfonyl group)

A salt system having an anion having a fluorine group and a sulfonyl group is easily dissolved in a polyether ester plasticizer and a polyether plasticizer, and the salt concentration in the plasticizer can be increased. By dispersing this solution in the adhesive composition for polarizers, a large amount of a salt having an anion having a fluorine group and a sulfonyl group can be uniformly taken into the adhesive composition for polarizers. In the adhesive composition for polarizers, the cations, which are the opposite ions of the anion, are coordinated with the oxygen atom of the ether in the plasticizer to form a complex.

A plasticizer solution in which a salt having an anion having a fluorine group and a sulfonyl group is dissolved. The adhesive composition for polarizers is matched with the plasticity of the plasticizer to impart antistatic performance while imparting plasticity. In addition, since the plasticizer containing a polyether group in the main chain can approach the solubility parameter (SP value) of the adhesive composition for polarizers, it has excellent affinity and does not bleed out. Furthermore, it is possible to obtain an adhesive composition for a polarizer that does not cause transitional pollution, does not depend on humidity, and has excellent fast-acting properties and continued excellent antistatic properties. The above-mentioned effects are also the same among the polyether ester plasticizer and the polyether plasticizer.

A plasticizer solution in which a salt having an anion having a fluoro group and a sulfonyl group is dissolved is in an adhesive composition for a polarizer to maintain adhesive properties and exhibit antistatic properties. Furthermore, a plasticizer solution containing a salt having an anion having a fluorine group and a sulfonyl group has excellent compatibility with the molecules constituting the adhesive composition for a polarizer, so that no exudation, dispersion, and migration can be obtained. Pollution-free adhesive composition for polarizers that does not depend on humidity, has excellent fast-acting properties, and has consistently superior antistatic properties.

The anion having a fluoro group and a sulfofluorenyl group is preferably selected from the group consisting of a bis (fluoroalkylsulfonyl) fluorenimide ion, a (fluoroalkylsulfonyl) methyl metal compound ion, and a fluoroalkylsulfonic acid ion. Group of anions.

The salt having an anion having a fluorine group and a sulfonyl group is preferably composed of at least one cation selected from the group consisting of an alkali metal, a Group 2 element, a transition metal, and an amphoteric metal, and the above-mentioned anion having a fluorine group and a sulfonyl group Of salt. Further, the salt having an anion having a fluoro group and a sulfofluorenyl group is particularly preferably an alkali metal salt of a bis (fluoroalkylsulfonyl) fluorenimide ion, and a fluoro (sulfoalkylsulfonyl) methyl metal compound ion. Alkali metal salts and alkali metal salts of fluoroalkyl sulfonate ions. Particularly preferred is a lithium salt.

There are many salts formed by the above anions and cations. Among them, bis (fluoroalkylsulfonyl) fluorenimide ion, gins (fluoroalkylsulfonyl) methyl metal compound ion, and fluoroalkane are preferred. Sulfonic acid ions, more preferably selected from alkali metal salts of bis (fluoroalkylsulfonyl) fluorenimide, alkali metal salts of gins (fluoroalkylsulfonyl) methyl metal compounds, and fluoroalkyl groups A group of salts of alkali metal salts of sulfonic acids. Specifically, lithium bis (trifluoromethanesulfonyl) fluorenimide Li (CF ₃ SO ₂ ) ₂ N and potassium bis (trifluoromethanesulfonyl) fluorenimide K (CF ₃ SO ₂ ) are preferred. ₂ N, bis (trifluoromethanesulfonyl) sulfonium sodium imine Na (CF ₃ SO ₂ ) ₂ N, ginseng (trifluoromethanesulfonyl) methylated lithium Li (CF ₃ SO ₂ ) ₃ C, ginseng (Trifluoromethanesulfonyl) potassium methoxide K (CF ₃ SO ₂ ) ₃ C, ginseng (trifluoromethanesulfonyl) sodium methylate Na (CF ₂ SO ₂ ) ₃ C, lithium trifluoromethanesulfonate Li (CF ₃ SO ₃ ), potassium trifluoromethanesulfonate K (CF ₃ SO ₃ ), sodium trifluoromethanesulfonate Na (CF ₃ SO ₃ ). Among them, lithium bis (trifluoromethanesulfonyl) fluorenimide, lithium ginseng (trifluoromethanesulfonyl) methylate, and lithium trifluoromethanesulfonate can be mentioned. Particularly preferred are lithium bis (trifluoromethanesulfonyl) fluorenimide and lithium trifluoromethanesulfonate; by adding a small amount of these, the above effects can be more exerted.

As shown in Fig. 1, lithium bis (trifluoromethanesulfonyl) fluorenimide is used as a salt, and it is dissolved in a polyetherester plasticizer composed of diethylene glycol and adipic acid, and becomes lithium ion The state of an ether oxygen atom in a polyethylene glycol. If an adhesive layer is formed using an adhesive composition for a polarizer, an adhesive layer in which lithium ions are uniformly dispersed is formed according to a state in which lithium ions are coordinated with ether oxygen atoms. In addition, in the adhesive layer, lithium ions are in a state where they can be easily moved by molecules of ether oxygen. When an electric field is applied from the outside, lithium ions move (corresponding to ion transport) to the corresponding poles in the adhesive layer, thereby expressing ion transmission properties.

The so-called bis (fluoroalkylsulfonyl) fluoride lithium imide Li (CF ₃ SO ₂ ) ₂ N is in a state of being dissolved in tetraethylene glycol dimethyl ether, and the ether group belonging to the polar group is coordinated with Li ⁺ ion. The state is dispersed in the composition. That is, the composition contains a lithium polyether complex. Li ⁺ ions are surrounded by ether oxygen and detached from (CF ₃ SO ₂ ) ₂ N ^- ions, and become naked, which greatly contributes to antistatic properties. Especially, the mixture of lithium salt and plasticizer containing polyether group in the main chain forms a Lewis acid and base type ion. This type of compound acts as an ionic liquid and is particularly helpful for antistatic properties. . In addition, the lithium salt forms a Lewis acid · base type ion with a plasticizer containing a polyether group in the main chain, so it cannot form a chemical bond with the iodine ion of the polarizer. Therefore, it does not cause discoloration of the polarizer.

The salt having an anion having a fluoro group and a sulfonyl group is preferably 0.1 to 200 parts by mass, more preferably 1 to 180 parts by mass, based on 100 parts by mass of the plasticizer containing a polyether group in the main chain. More preferably 5 to 150 parts by mass.

The plasticizer solution containing a salt having an anion having a fluorine group and a sulfonyl group is preferably contained in an amount of 0.01 to 30 parts by mass based on 100 parts by mass of the (meth) acrylic copolymer. When the content of the plasticizer solution in which the salt having an anion having a fluorine group and a sulfonyl group is dissolved is set within the above range, sufficient antistatic performance can be exhibited.

(Polymer type antistatic agent)

The antistatic composition may further contain a polymer-type antistatic agent. Polymeric antistatic agents can stabilize salts with anions. In addition, since the salt having an anion is dispersed in a state of being dissolved in a plasticizer containing a polyether group in the main chain, it is considered that the salt is concentrated in polymerization having affinity with the plasticizer containing a polyether group in the main chain. The presence of the bulk antistatic agent is stabilized by the affinity of the two. Examples of such a polymer-type antistatic agent include a polyether block polyolefin copolymer, a polyoxyalkylene-based copolymer, and an ethylene oxide-propylene oxide-allyl epoxy propylene copolymer.

The polymer-type antistatic agent is preferably contained in an amount of 0.1 to 65 parts by mass based on 100 parts by mass of the (meth) acrylic copolymer.

(Manufacturing method of antistatic composition)

The method for producing an antistatic composition used in the present invention includes: an ether oxygen atom of a plasticizer containing a polyether group in a main chain; and a phase corresponding to an anion having a fluorine group and a sulfonyl group. Step of salt solution in the state of cations. In the step of preparing a salt solution, a plasticizer containing a polyether group in the main chain rapidly dissolves a salt having an anion having a fluorine group and a sulfonyl group under heat generation. In the present invention, the plasticizer containing a polyether group in the main chain is preferably a polyether ester-based plasticizer and / or a polyether-based plasticizer; a salt solution is added with these plasticizers and has a fluorine group and a sulfonium It is obtained by stirring an anion salt of a radical, and the like.

(Adhesive composition)

It is preferable that the adhesive composition for polarizers is an adhesive composition which does not contain a carboxyl group substantially as a main component. Here, the term "substantially does not contain a carboxyl group" means that when the acid value of the monomer used for polymerization of the adhesive composition is measured in accordance with JIS K0070 (1992), the acid value is less than 0.1 mgKOH / g. If the acid value is less than 0.1 mgKOH / g, it means that no carboxyl group-containing monomer is intentionally added.

(Acrylic Adhesive Composition)

The main component of the adhesive composition for polarizers is an acrylic adhesive composition. The acrylic adhesive composition contains a (meth) acrylic copolymer which is crosslinked by a crosslinking agent. The "main component" means that the content is 50% by mass or more based on the entire adhesive.

The acrylic adhesive composition contains a (meth) acrylic copolymer (A) and a crosslinking agent (B). The "acrylic adhesive composition" is a compound having a (meth) acrylfluorenyl group. "(Meth) acrylfluorenyl" means acrylfluorenyl or methacrylfluorenyl.

The (meth) acrylic copolymer (A) is preferably at least 60% to 99.99% by mass of (i) a (meth) acrylate monomer having an alkyl group having 1 to 18 carbon atoms and (ii) having a radical 0.01 to 20% by mass of a polymerizable unsaturated group and a monomer having at least one reactive functional group are polymerized and obtained.

Examples of (i) a (meth) acrylate monomer having an alkyl group having 1 to 18 carbon atoms (hereinafter referred to as a non-crosslinkable acrylic monomer) include a hydrogen atom of a carboxyl group of (meth) acrylic acid (Meth) acrylate substituted with a hydrocarbyl group. The carbon number of the hydrocarbon group is preferably 1 to 18, and more preferably 1 to 8. This hydrocarbon group may have a substituent. The substituent is not particularly limited as long as it does not contain a crosslinkable group, and examples thereof include alkoxy groups such as methoxy and ethoxy. Specific examples of the (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, and (meth) ) N-butyl acrylate, isobutyl (meth) acrylate, n-butyl (meth) acrylate, n-amyl (meth) acrylate, n-hexyl (meth) acrylate, 2-ethyl (meth) acrylate Hexyl ester, n-octyl (meth) acrylate, isooctyl (meth) acrylate, n-nonyl (meth) acrylate, isononyl (meth) acrylate, n-decyl (meth) acrylate, (formyl) Base) isodecyl acrylate, n-undecyl (meth) acrylate, n-dodecyl (meth) acrylate, stearyl (meth) acrylate, methoxyethyl (meth) acrylate, (methyl) ) Ethoxyethyl acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate. These may be used alone or in combination of two or more. In the present invention, "(meth) acrylic acid" means both "acrylic acid" and "methacrylic acid". Among these, from the viewpoint of adhesion, n-butyl acrylate, 2-ethylhexyl acrylate, and methyl acrylate are preferred.

The amount of the non-crosslinkable acrylic monomer used for the polymerization of the (meth) acrylic copolymer (A) is preferably 60 to 99.99% by mass, and more preferably 65 to 99.99% by mass. If the amount of non-crosslinkable acrylic monomer used in the polymerization is above the lower limit value, Above, sufficient adhesion can be exhibited, and if it is below the above upper limit, crosslinking can be sufficiently performed.

(ii) A monomer having a radical polymerizable unsaturated group and at least one reactive functional group (hereinafter referred to as a crosslinkable monomer), if it can be polymerized with a non-crosslinkable acrylic monomer , It may be an acrylic monomer or a non-acrylic monomer, preferably an acrylic monomer. Examples of the reactive functional group include a carboxyl group, a hydroxyl group, an amine group, an epoxy group, and an epoxy group.

As the carboxyl group-containing monomer, for example, α, β-but Saturated carboxylic acid or its anhydride.

Examples of the hydroxyl-containing monomer include 2-hydroxyethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and 2-hydroxypropyl (meth) acrylate. Esters, (meth) acrylic acid such as (meth) acrylic acid mono (diethylene glycol) [(mono, di, or more) ethylene glycol], (meth) acrylic acid such as (meth) acrylic monocaprolactone, etc. Lactone.

Examples of the amine group-containing monomer include (meth) acrylamide, allylammonium, N, N-dimethyl (meth) acrylamide, and N-butyl (meth) acrylamide Wait.

Examples of the glycidyl group-containing monomer include glycidyl (meth) acrylate.

The amount of the crosslinkable monomer used for the polymerization of the (meth) acrylic copolymer (A) is preferably 0.01 to 20% by mass, more preferably 0.03 to 10% by mass, and still more preferably 0.05 to 10% by mass. If the amount of the crosslinkable monomer used in the polymerization is above the lower limit value, sufficient cross-linking can be achieved; if the amount is below the upper limit value, it is easy to control the adhesive force, re-peel and reuse the glass reworkability Also good.

From the viewpoint of good adhesion, crosslinkability, polymerizability, and durability, and then re-peelability, recyclability of the glass is good, the crosslinkable monomer is preferably a hydroxyl group-containing monomer. Monomer or amine-containing monomer. A hydroxyl-containing monomer and an amine-containing monomer may be used in combination. As the hydroxyl group-containing monomer, hydroxyalkyl (meth) acrylate is preferred, and 2-hydroxyethyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate are particularly preferred. As the amine group-containing monomer, (meth) acrylamide, N, N-dimethyl (meth) acrylamide, and N-butyl (meth) acrylamide are preferred.

In the case where the crosslinkable monomer is a carboxyl group-containing monomer, since the acidity becomes strong, contact with a corrosive film such as a tin-doped indium oxide film or a metal film may cause corrosion of these films. Therefore, from the viewpoint of preventing corrosion, the amount of the carboxyl group-containing monomer used for polymerization of the (meth) acrylic copolymer (A) is preferably less than 0.5% by mass, and more preferably less than 0.05% by mass. . The monomer having a reactive functional group is preferably substantially free of a carboxyl group-containing monomer. Here, the monomer having a reactive functional group does not substantially contain a carboxyl group-containing monomer, and means that the monomer having a reactive function is used for measuring the polymerization of the (meth) acrylic copolymer (A) in accordance with JIS K0070 (1992). When the acid value of the functional group monomer is less than 0.1 mgKOH / g. If the acid value of the monomer having a reactive functional group is less than 0.1 mgKOH / g, it can be considered that it does not contain a carboxyl group-containing monomer intentionally added; if it is 0.1 to 1.0 mgKOH / g, it can be considered that it contains a deliberate addition. Carboxyl-containing monomer. The term "intentional addition" refers to the use of a carboxyl group-containing monomer as the crosslinkable monomer. When using acrylates (derivatives derived from acrylic acid) which are non-crosslinkable acrylic monomers, although there may be traces of unreacted acrylic acid in the form of impurities, such cases are not considered to be intentional additions.

When the acid value is measured according to JIS K0070 (1992), the measurement is performed, for example, as follows.

A precision flat scale is used to measure about 2 g of the sample in a 100 ml conical flask, and 10 ml of a mixed solvent of ethanol / diethyl ether = 1/1 (weight ratio) is added to dissolve the sample. Furthermore, add 1 to 3 drops of phenolphthalein ethanol solution as an indicator in this container, and stir well until the sample is uniform stop. This was titrated with a 0.1 N potassium hydroxide-ethanol solution, and the neutralization endpoint was used when the indicator continued to be reddish for 30 seconds. From this result, the value obtained using the following calculation formula (1) was used as the acid value of the sample.

Acid value (mgKOH / g) = [B × f × 5.611] / S (1)

In the calculation formula (1), B is the usage amount (ml) of 0.1N potassium hydroxide-ethanol solution, f is a factor of 0.1N potassium hydroxide-ethanol solution, and S is the amount of sample taken (g).

The (meth) acrylic copolymer (A) may have a monomer other than a non-crosslinkable acrylic monomer and a crosslinkable monomer. Examples of other monomers include (meth) acrylonitrile, vinyl acetate, styrene, vinyl chloride, vinylpyrrolidone, and vinylpyridine.

The amount of other monomers used in the polymerization of the (meth) acrylic copolymer (A) is preferably 0.1 to 20% by mass, and more preferably 0.5 to 10% by mass. If the amount of other monomers used in the polymerization is greater than or equal to the above-mentioned lower limit value, physical properties can be easily adjusted, and if it is less than or equal to the above-mentioned upper limit value, yellowing due to deterioration with time can be prevented.

(Weight average molecular weight of (meth) acrylic copolymer)

The weight average molecular weight of the (meth) acrylic copolymer (A) is preferably 400,000 to 2.5 million, more preferably 500,000 to 2 million, even more preferably 1 to 2 million, and particularly preferably 1.5 to 2 million. When the weight average molecular weight is within the above range, sufficient cohesive force can be exhibited, and durability can be improved. Furthermore, it is possible to suppress an increase in the viscosity of a coating solution containing an adhesive composition for a polarizer, and it is easy to form an adhesive layer by coating. The weight average molecular weight can be measured using gel permeation chromatography (GPC), and is the weight average molecular weight converted to standard polystyrene (PS).

(Crosslinking agent used in acrylic adhesive composition)

As the cross-linking agent (B) used in the acrylic pressure-sensitive adhesive composition, a cross-linking agent capable of reacting with a cross-linkable monomer which is a monomer having a reactive functional group is preferably used. Examples thereof include an isocyanate-based crosslinking agent, an epoxy-based crosslinking agent, Oxazoline crosslinking agent, acryl Cross-linking agent, metal clamp agent-based cross-linking agent, butylated melamine-based cross-linking agent, and the like. Among these crosslinking agents, since the (meth) acrylic copolymer (A) can be easily crosslinked, an isocyanate-based crosslinking agent, an epoxy-based crosslinking agent, and a metal clamp agent-based crosslinking agent are preferred. In particular, when the (meth) acrylic copolymer (A) contains only a hydroxyl-containing monomer as a crosslinkable monomer, it is preferable to use an isocyanate-based crosslinking agent from the viewpoint of the reactivity of the hydroxyl group.

Examples of the isocyanate-based crosslinking agent include cresyl diisocyanate, ditolyl diisocyanate, hexamethylene diisocyanate, and isophorone diisocyanate. Examples of the epoxy-based crosslinking agent include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, and glycerin. Diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, tetraglycidyl xylene diamine, 1,3-bis (N, N-Diglycidylaminomethyl) cyclohexanone, trimethylolpropane polyglycidyl ether, diglycerol polyglycidyl ether, polyglycerol polyglycidyl ether, sorbitol polycyclic Oxypropyl ether and so on. The content of the cross-linking agent is preferably appropriately selected in accordance with the required adhesive properties. These crosslinking agents can be used alone or in combination of two or more.

The content of the crosslinking agent (B) used in the acrylic adhesive composition is preferably 0.001 to 10 parts by mass, and more preferably 0.01 to 5 parts with respect to 100 parts by mass of the (meth) acrylic copolymer (A). Parts by mass. If it is more than the said lower limit, foaming can be suppressed, and if it is below the said upper limit, it can have sufficient stress relaxation performance.

(additive)

The adhesive composition for polarizers of this invention may contain components other than an acrylic adhesive composition and an antistatic composition. For example, in addition to the acrylic adhesive composition, a polyester resin, an amine resin, an epoxy resin, and a polyurethane resin may be used in combination.

Moreover, the adhesive composition for polarizers of the present invention may contain a light stabilizer such as an antioxidant, a metal corrosion inhibitor, an adhesion-imparting agent, a silane coupling agent, an ultraviolet absorber, a hindered amine compound, and the like, as necessary. Additives and other additives. Examples of the antioxidant include a phenol-based antioxidant, an amine-based antioxidant, a lactone-based antioxidant, a phosphorus-based antioxidant, and a sulfur-based antioxidant. These antioxidants may be used individually by 1 type, and may use 2 or more types together. As the metal corrosion inhibitor, a benzotriazole-based resin is preferred in terms of improving the compatibility or effect of the adhesive. Examples of the adhesion-imparting agent include rosin-based resins, terpene-based resins, terpene-based resins, benzofuran-indene-based resins, styrene-based resins, xylene-based resins, phenol-based resins, and petroleum resins. Examples of the silane coupling agent include a mercaptoalkoxysilane compound (for example, a mercapto-substituted alkoxy oligomer). Examples of the ultraviolet absorber include benzotriazole-based compounds, diphenylketone-based compounds, Department of compounds and so on.

The content of these additives is 100 parts by mass with respect to the solid content of the adhesive composition for polarizers, usually preferably 0.01 to 10 parts by mass, more preferably 0.05 to 5 parts by mass, and particularly preferably 0.1 to 3 parts by mass.

(Manufacturing method of adhesive composition for polarizers)

The adhesive composition for polarizers is a salt containing an anion having a fluoro group and a sulfonyl group in an adhesive resin-containing composition such as an acrylic adhesive composition. While manufacturing. The production method includes a step of preparing a salt solution prepared by dissolving a salt having an anion having a fluorine group and a sulfonyl group in a plasticizer containing a polyether group in a main chain; a salt solution (first component) and A step of kneading the adhesive resin (second component) to form a composition; a step of further mixing or blending the composition with the adhesive resin (second component). By kneading the first component and the second component, the salt solution is dispersed or dissolved in the form of fine droplets in the composition. Then, the salt is dissolved in the composition according to the state, and then kneaded or blended with the adhesive resin (second component), so the salt is dispersed in the adhesive resin (second component) in a more uniform affinity state.

(Adhesive sheet for polarizers)

The adhesive composition for polarizers of the present invention can be formed into a sheet shape to form an adhesive sheet for polarizers. The adhesive sheet for polarizers can be manufactured, for example, by dissolving an adhesive in a solvent and removing the solvent after coating. As a coating method, a knife coater, a micro-rod coater, an air knife coater, a reverse roll coater, a reverse gravure coater, a Vario gravure coater, a die coater, a curtain coater, etc. Choose appropriately. If the adhesive sheet of the present invention is used, the step of applying and drying the adhesive at the bonding stage is not required. If an adhesive sheet is laminated and pressed between the optical film and the object to be adhered, the adhesive can be adhered, which is quite simple. .

(Thickness of Adhesive Sheet for Polarizers)

The thickness of the adhesive layer of the adhesive sheet for a polarizer of the present invention is preferably 100 μm or less, and more preferably 5 to 50 μm. If it is below the above upper limit value, the stress relaxation performance of the adhesive layer can be sufficiently expressed.

(Adhesive sheet for polarizer appliance release sheet)

It is preferable that the adhesive sheet of a polarizer tool release sheet has a structure in which a release film provided with a release agent on a substrate is provided on one or both sides of the adhesive sheet. For example, a double-sided adhesive sheet with a release sheet having release films provided on both sides of the adhesive layer is formed on the release layer of the first release film provided with a release layer on the polymer film, and the adhesive coating solution is applied. After the cloth is dried, a peeling layer of a second peeling film composed of a peeling agent layer having a peeling force different from that of the first peeling film is bonded and pressure-bonded to the adhesive layer. When the peeling force of the first peeling film and the second peeling film are close to each other, when the peeling film on the light peeling force side is peeled off, separation of the adhesive from the peeling film on the heavy peeling force side will occur. Therefore, the peeling force of the peeling film on the heavy peeling force side is preferably 0.05N to 0.15N, and the peeling force of the peeling film on the light peeling force side is preferably 0.01 to 0.04N.

At this time, when the difference in the peeling force between the two release films is maintained, the adhesive coating solution may be first applied to the second release film, and then the first release film may be bonded and pressure-bonded. The shape of the adhesive sheet may be a sheet shape, or it may be rolled up into a roll shape.

(Polarizer)

The adhesive composition for polarizers and the adhesive sheet for polarizers of the present invention can be directly attached (laminated) to the polarizer. FIG. 2 (a) shows a polarizing plate when the adhesive composition and a sheet for a polarizer of the present invention are used. As shown in FIG. 2 (a), an adhesive sheet (adhesive composition layer for a polarizer) 20 is directly attached to the polarizer 10. Moreover, an adhesive sheet (adhesive composition layer for polarizers) 20 may be attached to both surfaces of the polarizer 10.

FIG. 2 (b) shows the structure of a conventional polarizing plate. In the conventional polarizing plate, the polarizer is held by a protective film, and an adhesive sheet (adhesive layer) is attached to the protective film. The adhesive composition and the adhesive sheet for a polarizer of the present invention can also be applied to such a structure, but as shown in FIG. 2 (a) Generally, the effect of the present invention can be exerted when directly attached to a polarizer.

The adhesive composition for polarizers and the adhesive sheet for polarizers of the present invention are used for bonding a polarizer to a member having a thickness of 100 μm, preferably 1 mm or more. Moreover, the adhesive composition for polarizers and the adhesive sheet for polarizers of the present invention are used for bonding a polarizer to an optical member. As an optical member, a liquid crystal cell, a touch panel, etc. can be mentioned, for example, and the image display apparatus provided with the adhesive sheet of this invention can be manufactured.

As a polarizer used for a polarizing plate, for example, a polyvinyl alcohol-based resin film or a polyvinyl alcohol-based resin described in Japanese Patent Laid-Open No. 2012-159778 is used to adsorb and align a dichroic dye. The polyvinyl alcohol-based resin constituting the polarizer is obtained by saponifying a polyvinyl acetate-based resin. As the polyvinyl acetate-based resin, in addition to polyvinyl acetate, which is a homopolymer of vinyl acetate, copolymers of vinyl acetate and other monomers that can be copolymerized therewith can be exemplified. Examples of other monomers copolymerized with vinyl acetate include unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, and acrylamides having an ammonium group. The saponification degree of the polyvinyl alcohol resin is usually about 85 to 100 mol%, preferably more than 98 mol%. This polyvinyl alcohol-based resin can be further modified, for example, polyvinyl formaldehyde or polyvinyl acetaldehyde modified by aldehydes can be used. The degree of polymerization of the polyvinyl alcohol resin is usually about 1,000 to 10,000, preferably about 1,500 to 5,000.

Those who make such polyvinyl alcohol-based resin into a film use an original film as a polarizer. The method of forming a polyvinyl alcohol-type resin into a film is not specifically limited, It can form into a film by a well-known method. The film thickness of the original film made of a polyvinyl alcohol-based resin is not particularly limited, and is, for example, about 1 to 150 μm. Considering the ease of stretching, the film thickness is preferably 3 μm or more.

In addition, the above-mentioned polyvinyl alcohol-based resin film or Japanese patent The step of uniaxially stretching the polyvinyl alcohol-based resin described in JP 2012-159778, the step of dyeing the polyvinyl alcohol-based resin or film with a dichroic dye and adsorbing the dichroic dye, A step of treating a polyvinyl alcohol-based resin or film of a chromatic dye with a boric acid aqueous solution, a step of washing the boric acid aqueous solution after the treatment, and finally drying and manufacturing.

The polarizing plate has a structure in which a transparent protective film is laminated on at least one of the polarizers manufactured as described above. As the transparent protective film, a film made of a suitable transparent resin can be used. Specifically, it is preferable to use a polymer composed of a polymer having excellent transparency, uniform optical characteristics, mechanical strength, and thermal stability. As such a transparent resin film, cellulose-based films such as triethyl cellulose and diethyl cellulose, polyethylene terephthalate, polyethylene isophthalate, and terephthalic acid can be used. Polyester films such as butane formate, acrylic resin films such as poly (meth) acrylate and poly (meth) acrylate, polycarbonate films, polyether fluorene films, polyfluorene Film, polyimide-based film, polyolefin-based film, polymer The olefin-based film and the like are not limited thereto.

[Example]

The following examples and comparative examples will more specifically describe the features of the present invention. The materials, usage amounts, proportions, processing contents, processing procedures, etc. shown in the following examples can be appropriately changed without departing from the gist of the present invention. Therefore, the scope of the present invention is not limited to the specific examples shown below. In addition, the "part" and "%" in the examples are "mass parts" and "mass%", respectively, without limitation.

(Manufacturing example 1) <Preparation of (meth) acrylic copolymer (A-1)>

In a reaction vessel equipped with a cooling tube, a nitrogen introduction tube, a stirrer, and a thermometer, 80 parts of ethyl acetate was added, and 65 parts of butyl acrylate, 30 parts of 2-ethylhexyl acrylate, and 2-hydroxyethyl acrylate were charged as monomers. 5 parts of ester was sealed with nitrogen to make it oxygen-free, and the internal temperature was raised to 55 ° C. Thereafter, a total amount of a solution in which 0.06 parts of azobisisobutyronitrile (polymerization initiator) was dissolved in 10 parts of ethyl acetate was added. Thereafter, the mixture was stirred while maintaining the temperature, and after stirring for 12 hours, it was cooled to stop the polymerization reaction. The obtained (meth) acrylic copolymer (A-1) was a polystyrene-equivalent weight average molecular weight Mw measured by GPC of 1.5 million.

(Measurement of weight average molecular weight of (meth) acrylic copolymer)

The weight average molecular weight Mw of the (meth) acrylic copolymer is a sample in which THF (tetrahydrofuran) is dissolved by GPC (gel permeation chromatography) measurement.

(Manufacturing example 2) <Preparation of (meth) acrylic copolymer (A-2)>

In a reaction vessel equipped with a cooling tube, a nitrogen introduction tube, a stirrer, and a thermometer, 80 parts of ethyl acetate was added, and 65 parts of butyl acrylate, 30 parts of 2-ethylhexyl acrylate, and 2-hydroxyethyl acrylate were charged as monomers. 5 parts of the ester was sealed with nitrogen to make it oxygen-free, and the internal temperature was raised to 45 ° C. Thereafter, a total amount of a solution in which 0.04 parts of azobisisobutyronitrile (polymerization initiator) was dissolved in 10 parts of ethyl acetate was added. Thereafter, the mixture was stirred while maintaining the temperature, and after stirring for 16 hours, it was cooled to stop the polymerization reaction. The obtained (meth) acrylic copolymer (A-2) had a polystyrene-equivalent weight average molecular weight Mw measured by GPC of 1.8 million.

(Manufacture example 3) <Production of Polarizer>

A 75 μm thick polyvinyl alcohol film (average degree of polymerization of about 2,400, degree of saponification of 99.9 mol% or more) was uniaxially stretched to about 5 times by dry stretching, and then kept under tension, immersed in pure water at 60 ° C After 1 minute, immerse it in an aqueous solution having a weight ratio of iodine / potassium iodide / water of 0.05 / 5/100 at 28 ° C for 60 seconds. Thereafter, it was immersed in an aqueous solution having a weight ratio of potassium iodide / boric acid / water at 8.5 / 8.5 / 100 at 72 ° C for 300 seconds. Subsequently, it was washed with pure water at 26 ° C. for 20 seconds, and then dried at 65 ° C. to obtain a polarizer having a thickness of 28 μm with iodine adsorbed and aligned on a polyvinyl alcohol film. Secondly, on one side of this polarizer, 3 parts of carboxyl-modified polyvinyl alcohol [trade name "KL-318" obtained from Kuraray Co., Ltd.] was dissolved with respect to 100 parts of water. Polyamide epoxy-based additive for water-soluble epoxy resin [trade name "Sumirez Resin 650 (30)" obtained from Taoka Chemical Industry Co., Ltd., 30% solid solution in water] 1.5 parts of epoxy-based adhesive The polarizer was coated with an agent to produce a 40 μm-thick triacetyl cellulose film (TAC) [trade name “KC4UY” manufactured by Konica Minolta (KK) Co., Ltd.] as a transparent protective film.

(Example 1) <Preparation of acrylic adhesive solution>

With respect to 100 parts of the solid content of the (meth) acrylic copolymer (A-1) obtained in Production Example 1, 0.1 part of xylene diisocyanate (manufactured by Mitsui Chemicals Corporation: TAKENATE 500) as a crosslinking agent was added and 3- 0.1 part of glycidoxypropylmethoxysilane (manufactured by Shin-Etsu Chemical Industry Co., Ltd .: KBM-403), and 50 parts of polyetherester-based compound (Monocizer (registered trademark) W-262 and Polycizer (registered trademark)) A composition in which 50 parts of lithium bis (trifluoromethanesulfonyl) fluorenimide was dissolved in W-230-H (1: 1 mixture) 2.5 As an antistatic composition, an acrylic adhesive solution was prepared by diluting ethyl acetate to a solution having a solid content concentration of 15%.

<Production of adhesive sheet>

A 38 μm-thick polyethylene terephthalate film (separation film) having a release agent layer treated with a polysiloxane-based release agent was prepared from the adhesive solution prepared as described above (manufactured by Oji F-TEX: 38RL). -07 (2)), the coating amount was uniformly applied by an applicator so that the coating amount after drying became 20 μm / m ² , and dried in an air circulation constant temperature oven at 100 ° C. for 3 minutes to form on the surface of the separation film Adhesive layer. Next, a 38 μm separation film (manufactured by Oji F-TEX: 38RL-07 (L)) was laminated on the surface of the adhesive layer to obtain a device having an adhesive layer held by a separation film having a difference in peeling force and having Adhesive sheet consisting of release film / adhesive layer / release film. The adhesive sheet was cured for 7 days at 23 ° C and 50% relative humidity.

<Production of Polarizer with Adhesive Layer>

The release film of the release agent layer having a lighter peeling force of the adhesive sheet was peeled off, and the adhesive layer was directly transferred (attached) to the polarizing layer side of the polarizer of the polarizing plate obtained in Production Example 3 to produce an adhesive layer. Polarizer.

(Example 2) <Preparation of acrylic adhesive solution>

With respect to 100 parts of the solid content of the (meth) acrylic copolymer (A-2) obtained in Production Example 2, 0.1 part of xylene diisocyanate (manufactured by Mitsui Chemicals Corporation: TAKENATE 500) as a crosslinking agent was added and 3- Glycidoxypropylmethoxysilane (Shin-Etsu Chemical Co., Ltd. Co., Ltd .: KBM-403) 0.1 part, and it was added to 50 parts of polyetherester compound (1: 1 mixture of Monocizer (registered trademark) W-262 and Polycizer (registered trademark) W-230-H)) 1.8 parts of a composition of 50 parts of lithium bis (trifluoromethanesulfonyl) fluorenimide was used as an antistatic composition, and ethyl acetate was diluted to a solution having a solid content concentration of 15% to prepare an acrylic adhesive solution.

<Production of adhesive sheet>

An adhesive sheet was produced in the same manner as in Example 1.

<Production of Polarizer with Adhesive Layer>

A polarizing plate with an adhesive layer was produced in the same manner as in Example 1.

(Example 11) <Preparation of acrylic adhesive solution>

With respect to 100 parts of the solid content of the (meth) acrylic copolymer (A-1) obtained in Production Example 1, 0.1 part of xylene diisocyanate (manufactured by Mitsui Chemicals Corporation: TAKENATE 500) as a crosslinking agent was added and 3- 0.1 part of glycidoxypropylmethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd .: KBM-403) was added to 50 parts of polyalkylene glycol (di / mono) alkyl ether compound, and bis (trifluoro) was dissolved. 2.5 parts of a composition of 50 parts of methanesulfonyl) fluorene lithium imide was used as an antistatic composition, and ethyl acetate was diluted to a solution having a solid content concentration of 15% to prepare an acrylic adhesive solution.

<Production of adhesive sheet>

A 38 μm-thick polyethylene terephthalate film (separation film) having a release agent layer treated with a polysiloxane-based release agent was prepared from the adhesive solution prepared as described above (manufactured by Oji F-TEX: 38RL). -07 (2)), the coating amount was uniformly applied by an applicator so that the coating amount after drying became 20 μm / m ² , and dried in an air circulation constant temperature oven at 100 ° C. for 3 minutes to form on the surface of the separation film Adhesive layer. Next, a 38 μm separation film (manufactured by Oji F-TEX: 38RL-07 (L)) was laminated on the surface of the adhesive layer to obtain a device having an adhesive layer held by a separation film having a difference in peeling force and having Adhesive sheet consisting of release film / adhesive layer / release film. The adhesive sheet was cured for 7 days at 23 ° C and 50% relative humidity.

<Production of Polarizer with Adhesive Layer>

The release film of the release agent layer having a lighter peeling force of the adhesive sheet was peeled off, and the adhesive layer was directly transferred (attached) to the polarizing layer side of the polarizer to the polarizing plate obtained in Production Example 3 to produce an adhesive layer. Of polarizing plate.

(Comparative example 1) <Preparation of acrylic adhesive solution>

In addition to replacing 50 parts of the polyetherester-based compound used in Example 1 (1: 1 mixture of Monocizer (registered trademark) W-262 and Polycizer (registered trademark) W-230-H)), bis (trifluoromethane) was dissolved A composition of 50 parts of lithium sulfonium) phosphonium imine, except that N-hexyl-4-methylimidazolium hexafluorophosphate (a solid at 25 ° C) was used as an ionic solid, the rest were the same as in Example 1. This was performed to obtain an acrylic adhesive solution.

<Production of adhesive sheet>

An adhesive sheet was produced in the same manner as in Example 1.

<Production of Polarizer with Adhesive Layer>

A polarizing plate with an adhesive layer was produced in the same manner as in Example 1.

(Comparative example 2) <Preparation of acrylic adhesive solution>

In addition to replacing 50 parts of the polyetherester-based compound used in Example 1 (1: 1 mixture of Monocizer (registered trademark) W-262 and Polycizer (registered trademark) W-230-H)), bis (trifluoromethane) was dissolved A composition of 50 parts of lithium sulfonium) phosphonium imine, except that epoxypropyltrimethylammonium trifluoromethanesulfonate (liquid at 25 ° C) was used as an ionic solid, and the rest were the same as in Example 1. This was performed to obtain an acrylic adhesive solution.

<Production of adhesive sheet>

An adhesive sheet was produced in the same manner as in Example 1.

<Production of Polarizer with Adhesive Layer>

A polarizing plate with an adhesive layer was produced in the same manner as in Example 1.

(Reference example 1) <Preparation of acrylic adhesive solution>

Except that 50 parts of the polyetherester-based compound used in Example 1 (a 1: 1 mixture of Monocizer (registered trademark) W-262 and Polycizer (registered trademark) W-230-H)) was not added, and bis (trifluoro An acrylic pressure-sensitive adhesive solution was obtained in the same manner as in Example 1 except that 50 parts of the composition of lithium methanesulfonyl) fluoreneimide was obtained.

<Production of adhesive sheet>

An adhesive sheet was produced in the same manner as in Example 1.

<Production of Polarizer with Adhesive Layer>

A polarizing plate with an adhesive layer was produced in the same manner as in Example 1.

(Evaluation) <Measurement of surface resistance value>

After the separation film of the polarizing plate with an adhesive layer cut to a size of 100 mm × 100 mm was peeled off, a resistance value measuring device (Hiresta-UP, MCP-HT450, manufactured by Mitsubishi Chemical Corporation) was used to measure the surface resistance value (Ω / □).

<Evaluation of Polarizer Durability>

After the separation film of the polarizing plate with an adhesive layer was peeled off, the adhesive surface was adhered to one side of a 0.7 mm-thick alkali-free glass (EAGLE XG, manufactured by Corning Corporation) to produce an optical laminate. Next, an autoclave treatment was performed at 50 ° C., 0.5 MPa, and 20 minutes to prepare an optical laminated body in which a polarizing plate having an adhesive layer was completely adhered to glass. The optical laminated body produced as described above was treated in a constant temperature and humidity tank at 85 ° C. (heat resistance test) for 500 hours, and the optical laminated body after the test was visually observed.

(Evaluation criteria)

○: No change in appearance such as lifting, peeling, or foaming was observed.

(Triangle | delta): The appearance change, such as a float, peeling, and foaming, was slight.

×: Apparent changes in appearance such as floating, peeling, and foaming were observed.

<Evaluation of optical durability (transmission hue)>

After the separation film of the polarizing plate with an adhesive layer was peeled off, the adhesive surface was adhered to one side of a 0.7 mm-thick alkali-free glass (EAGLE XG, manufactured by Corning Corporation) to produce an optical laminate. Next, an autoclave treatment was performed at 50 ° C., 0.5 MPa, and 20 minutes to prepare an optical laminated body in which a polarizing plate having an adhesive layer was completely adhered to glass. The optical laminated body produced as described above was processed in a constant temperature and humidity tank at 60 ° C and a relative humidity of 90% (humidity and heat resistance test) at the initial stage, 100 hours, 240 hours, and 500 hours, and each processing time was measured. The penetrating hue b value. The measurement system used a spectrocolorimeter (manufactured by Nippon Denshoku Co., Ltd .: SE6000). Using this measured value, the change amount Δb of the penetration hue before and after the test was calculated.

△ b value = measured value after test-initial value before test

<Evaluation of optical durability (780 nm transmittance)>

After the separation film of the polarizing plate with an adhesive layer was peeled off, the adhesive surface was adhered to one side of a 0.7 mm-thick alkali-free glass (EAGLE XG, manufactured by Corning Corporation) to produce an optical laminate. Next, an autoclave treatment was performed at 50 ° C., 0.5 MPa, and 20 minutes to prepare an optical laminated body in which a polarizing plate having an adhesive layer was completely adhered to glass. The optical laminated body produced as described above was processed in a constant temperature and humidity bath at 60 ° C. and a relative humidity of 90% (damp heat resistance test) at the initial stage, 100 hours, 240 hours, and 500 hours, and the transmittance T at 780 nm was measured at each processing time. Alas. The measurement system used a spectrophotometer (manufactured by Shimadzu Corporation: Solidspec-3700). Using this measured value, the amount of change in transmittance ΔT⊥ at 780 nm before and after the test was calculated.

△ T⊥ = (Measured value after treatment)-(Initial value)

<Measurement of Polarization>

After the separation film of the polarizing plate with an adhesive layer was peeled off, the adhesive surface was adhered to one side of a 0.7 mm-thick alkali-free glass (EAGLE XG, manufactured by Corning Corporation) to produce an optical laminate. Next, an autoclave treatment was performed at 50 ° C., 0.5 MPa, and 20 minutes to prepare an optical laminated body in which a polarizing plate having an adhesive layer was completely adhered to glass. The optical laminated body produced as described above was processed at an initial stage of 100 hours at 60 ° C. and a relative humidity of 90% (humidity and heat resistance test), and a spectrophotometer (manufactured by JASCO Corporation: V-7100) was used to measure the before and after processing The degree of polarization of the polarizing plate was used to calculate the amount of change ΔPy.

△ Py = (Measured value after treatment)-(Initial value)

(Visually confirm color change)

After the separation film of the polarizing plate with an adhesive layer was peeled off, the adhesive surface was adhered to one side of a 0.7 mm-thick alkali-free glass (EAGLE XG, manufactured by Corning Corporation) to produce an optical laminate. Next, an autoclave treatment was performed at 50 ° C., 0.5 MPa, and 20 minutes to prepare an optical laminated body in which a polarizing plate having an adhesive layer was completely adhered to glass. The optical laminated body produced as described above was treated in a constant temperature and humidity tank at 60 ° C. and a relative humidity of 90% (humidity and heat resistance test) for 500 hours, and the colorless change was visually confirmed.

<Analysis of the antistatic composition in the adhesive sheet (from peak detection of the complex)>

15 ml of acetonitrile was added to 0.2 g of the adhesive sheet produced in the example and the like, and subjected to ultrasonic treatment for 30 minutes, and then left to stand for one day (pretreatment). After concentrating to dryness, it was dissolved in 1 ml of acetonitrile, and the sample was filtered by a 0.45 μm filter as a measurement sample, and analyzed by HPLC (high-speed liquid chromatography). The HPLC (high-speed liquid chromatography) analysis system uses a system manufactured by WATERS: a Separations Module 2696 and a Photodiode Array Detector 996 as a detector. The detailed conditions of the HPLC analysis are as follows.

Column: XBridge C18, diameter 4.6 × 250mm (made by WATERS)

Column temperature: 30 ℃

Mobile phase: acetonitrile / water

Flow rate: 0.8mL / min

Detection: 225nm

The above evaluation results are shown in Table 1.

As can be seen from Table 1, in the examples, in addition to the durability of the polarizing plate, the optical durability was also excellent. That is, in the examples, even if left in a high-temperature, high-humidity environment for a long time, there is still little coloration and high light transmittance.

On the other hand, it was found that in the comparative example, the optical durability was poor. In particular, the polarizing plates of Comparative Examples 1 and 2 also had poor durability, and their functions as polarizing plates were deteriorated.

3 is an antistatic composition containing a complex compound from the top, an extract of the adhesive sheet containing the antistatic composition obtained in the example, and an extract of the adhesive sheet without the antistatic composition added. (Reference Example 1) HPLC (high-speed liquid chromatography) analysis results. As shown in the chromatogram of the extract of the adhesive sheet containing the antistatic composition in the middle section, the complex solution peak was detected by the extraction solution of the adhesive sheet to which the antistatic composition was added at a residence time of 15.0 minutes.

Claims (16)

An adhesive composition for a polarizer, comprising an antistatic composition and a (meth) acrylic copolymer (A); wherein the (meth) acrylic copolymer (A) is at least ( i) 60 to 99.99% by mass of a (meth) acrylate monomer having an alkyl group having 1 to 18 carbon atoms, and (ii) a monomer having a radical polymerizable unsaturated group and having at least one reactive functional group The polymer obtained by polymerizing 0.01 to 20% by mass; the single system having a reactive functional group does not substantially contain a carboxyl group-containing monomer; the antistatic composition is a plasticizer containing a polyether group in the main chain In 100 parts by mass, a composition containing 5 to 150 parts by mass of a salt having an anion having a fluorine group and a sulfonyl group is dissolved; and the content of the antistatic composition is based on the (meth) acrylic copolymer (A ) 100 parts by mass, 0.1 to 10 parts by mass. For example, the adhesive composition for polarizers in the scope of the first patent application, wherein the antistatic composition is a polyether ester plasticizer containing a polyether group in the main chain, and has a fluorine-containing and Composition of an anionic salt of a sulfonyl group. For example, the adhesive composition for polarizers in the second patent application range, wherein the polyether ester plasticizer contains at least one polyether ester plasticizer represented by the following formula (1) or (2); [Chemical 2] In formulas (1) and (2), m is an integer of 1 to 40, n is an integer of 1 to 20, and R represents an alkyl group. For example, the adhesive composition for polarizers in the first patent application range, wherein the antistatic composition is a polyether-based plasticizer containing a polyether group in the main chain, and has a fluorine-containing group and a sulfonic group. Composition of an anion salt of a fluorenyl group. For example, the adhesive composition for polarizers according to item 4 of the patent application, wherein the polyether plasticizer contains a polyether plasticizer having the following formula (11); R ¹ (OCH ₂ CH ₂ ) _n OR ² (11) In the formula, R ¹ represents an alkyl group having 1 to 12 carbon atoms, R ² represents a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, and n represents an integer of 3 to 6. For example, the adhesive composition for polarizers according to the first patent application range, wherein the antistatic composition contains: a polyether ester-based plasticizer containing a polyether group in the main chain; A composition of a salt of an anion of a sulfonyl group and a sulfofluorenyl group; and a composition in which a salt having an anion having a fluoro group and a sulfonyl group is dissolved in a polyether plasticizer containing a polyether group in the main chain. For example, the adhesive composition for polarizers according to any one of claims 1 to 6, wherein the adhesive composition for polarizers contains a crosslinking agent (B). For example, in the adhesive composition for polarizers according to item 7 of the application, wherein the reactive functional group is selected from at least one of a hydroxyl group and an amine group, the single system having a reactive functional group substantially does not contain Carboxy monomer. For example, the adhesive composition for polarizers in the seventh scope of the application for a patent, wherein the cross-linking agent (B) is selected from the group consisting of isocyanate-based cross-linking agents, epoxy-based cross-linking agents and metal clamp compound-based cross-linking agents. At least one. For example, the adhesive composition for a polarizing element according to any one of claims 1 to 6, wherein the above-mentioned anion system having a fluoro group and a sulfonyl group is selected from bis (fluoroalkylsulfonyl) sulfonium imine ions. Anion composed of ginseng (fluoroalkylsulfonyl) methyl metal compound ion and fluoroalkylsulfonic acid ion. For example, the adhesive composition for polarizers according to any one of claims 1 to 6, wherein the salt having an anion having a fluorine group and a sulfonyl group includes a salt selected from the group consisting of alkali metals, At least one cation of a Group 2 element, a transition metal, and an amphoteric metal; and the above-mentioned anion having a fluorine group and a sulfonyl group. For example, the adhesive composition for a polarizing element according to any one of claims 1 to 6, wherein the salt system having an anion having a fluorine group and a sulfofluorenyl group is selected from bis (fluoroalkylsulfonyl) fluorene A salt composed of an alkali metal salt of an imine, an alkali metal salt of a gins (fluoroalkylsulfonyl) methyl metal compound, and an alkali metal salt of a trifluoroalkylsulfonic acid. For example, the adhesive composition for polarizers according to any one of the claims 1 to 6, wherein the adhesive composition for polarizers is used for bonding a polarizer to an optical member. For example, the adhesive composition for a polarizer according to item 13 of the application, wherein the optical member is a liquid crystal cell or a touch panel. An adhesive sheet for polarizers, characterized in that it contains an adhesive composition for polarizers according to any one of claims 1 to 6. An image display device, characterized in that it includes at least one adhesive sheet with the scope of patent application No. 15.